With Bitcoin the entity holding your assets and operating the trading mechanisms are generally the same company. This leaves a customer in a weaker position and could allow the exchange/brokerage/bank to get away with shadier practices. They can do things like delay the execution of a transaction until it better benefits them. Or they can unillaterally suspend the ability to withdraw funds with no advance notice, just as what is happening here.
At the end of the day I don't have access to my money, or I have to call their "customer support" and spend hours explaining the problem that they created.
If the bank goes down completely (as in: goes bankrupt), my deposits are only guaranteed by the state up to a certain limit, which isn't that high.
Regulation and "liability" buy me very little in real terms.
Large banks do have bugs, and sometimes even admit it. [0][1]
The fractional reserve system basically means if there is a problem, you need to be the first at the counter. If you are not, you will only get a certain amount of money back.
[0] http://www.telegraph.co.uk/finance/2737388/Bug-crunches-Hali...
[1] http://www.independent.co.uk/news/uk/home-news/lloyds-bankin...
Edit to add: (But not quite the same as the one above)
http://www.dailymail.co.uk/news/article-2426519/Gang-arreste...
http://article.wn.com/view/2012/06/26/Lloyds_TSB_computer_gl...
In any system with deposit or investor insurance, e.g. the United States, you will get back the full insured amount (up to $250 000 for bank deposits, $500 000 for investor funds). Beyond that you will be treated as the senior creditor that, as a depositor or investor, you are. If you want more certainty as to the return of your capital, buy Treasuries.
I probably should have mentioned I am in the UK. You get back up to £170k here ($280k) but I guess my point still stands :-)
Edit: (Oh, that's for a married couple by the way. £85k if you're single.)
Stop, you're killing me here.
